Saturday, 9 September 2017

Transplants are fantastical but tricky beasts. In the last week alone it was reported that a 13 year old girl who died from a brain aneurysm and donated her organs helped eight different people - a record number for a single donor. However transplants can be challenging. They can be surgically complex, like in 2011 when nine-year-old Alannah Shevenell had six of her organs replaced in one incredible operation. Alannah had a massive tumour taking over her abdomen, which necessitated the removal of her stomach, liver, spleen, small intestine, pancreas and part of her oesophagus, along with the tumour. All of the removed organs were replaced with transplanted organs and Alannah is now back in school and thriving.

Transplants can also be emotionally complex. This was the case for a 44 year old Chinese man who received the world’s first penis transplant in 2006. He had been left with a 1cm penis stump following an accident, and in an impressive feat of surgery, surgeons gave him the penis from the cadaver of a 20-something year-old. Two weeks later they had to chop it off. Initially it appeared to have gone well, the blood supply was good and he could urinate through it, but the recipient asked for it to be removed. He couldn’t live with the idea of having a dead man’s penis.

This emotional impact of a transplant is not restricted to genitalia. A study in the Journal of Near-Death Studies interviewed 10 heart transplant recipients and their friends and family, and encountered some strange stories. There was the woman who felt her partner was a better lover since receiving a woman’s heart, and the recipient who reported feeling the impact of the car crash that killed her donor. This is a small sample size, and there is no good evidence or reason to believe a transplanted organ would affect people in this way. However this doesn’t detract from how these people feel, and it demonstrates the psychological fallout transplants can have.

Moving back to solid science, one of the major challenges when it comes to transplantation is rejection. This is when the immune system identifies the transplant as foreign tissue and launches an assault on it, causing damage that can end in the death of the organ, and therefore possibly the recipient. Rejection is more likely when the donor and recipient are a poor tissue match. This matching is largely based on a set of proteins called Human Leukocyte Antigens (HLAs) that are found on the surface of every single cell in our bodies. Our HLAs are like a barcode that identify our cells as our own. A transplanted organ is exceptionally unlikely to be a perfect match, so it’s HLAs are different from our own cells. If they are too different, the immune system successfully plays ‘spot-the-difference’ and targets the transplant for destruction. We can try and mitigate this by using drugs that suppress the immune system, but this immunosuppression puts the recipient at higher risk of developing infections.

Rejection is not a one way street - sometimes transplants attack their new bodies. For instance, bone marrow transplants effectively transplant a chunk of immune system into the new body in the form of white blood cells. These white blood cells attack their new body, in a phenomenon known as Graft Versus Host Disease (GVHD). This can result in symptoms as mild as a rash or as severe as intestinal bleeding and coma. Sometimes a touch of GVHD can actually be a good thing, like in leukaemia after chemotherapy, where the aggressive transplanted T cells can kill off some of the recipient’s remaining cancer cells.

As I said at the outset, transplants are fantastical but tricky. We’ve covered tricky, so I’d like to end on something fantastical: ‘thoes’ and designer vaginas. When someone loses their thumb, it has an understandably massive impact on the range of movements their hand can perform. One option to improve this range is to remove their big toe and put that in the place the thumb used to be, creating something called a ‘thoe’. The loss of the big toe generally has less impact on a person’s quality of life than having a missing thumb, and the thoe has the added benefit of avoiding rejection because it isn’t foreign tissue.

Another transplant type that avoids the issue of rejection is a designer vagina. In 2014, in the Lancet, doctors reported a first - they had created vaginas grown from the vulval cells of four girls born with Mayer-Rokitansky-Küster-Hauser Syndrome (MRKHS). MRKHS affects up to 1 in 1,500 female births, and leaves sufferers with a completely or partially absent vagina. By growing vulval cells on a synthetic scaffold the doctors were able to grow vaginas tailored to their recipients, and they were a remarkable success.After an average of 6.75 years, all the girls gave their new vaginas ratings well within the normal range for lubrication, arousal and orgasm. Pretty fantastical.

These stories, along with many more, can be found in my book Immune: HowYour Body Defends and Protects You, published by Bloomsbury Sigma on September 21st 2017

Saturday, 18 February 2017

Being a new parent is full of trials and tribulations. Some are practical challenges that you never envisaged in your life. Like trying to change a nappy on a vigorously rolling one year old without getting covered in poo. Others are more philosophical, like how do I raise a feminist? For this I turn to Eva and Jude, two children who were on a programme called the Secret Life Of Five-Year-Olds (if you haven’t seen it, find it on Channel 4, it’s immense). Why can’t girls be scientists? Jude, a 5-year-old boy, replies that they’d ‘make silly potions’. His companion, a 5-year-old girl named Eva, promptly volunteers ‘I extracted the DNA from a banana once’. Boom. Drops mic.

I’m not alone in thinking Eva is a feminist icon. I want to write to Eva’s mum and ask for a guide to raising a little girl who schools boys on karate and is aware of the suffragette movement. I suspect step one is to be a well informed feminist yourself. I asked my husband to name some famous females in science or medicine and he could name more than I could. Ugh. I have therefore been schooling myself on some of the less well celebrated, but seriously fierce, females that have blazed a trail in science or medicine. Let me share:

Image: American Red Cross

Clara Barton founded the American Red Cross in 1881 at the age of 60, and headed it for 23 years. This formidable lady also provided aid to soldiers during the American Civil War, venturing into the heart of the battlefield, where medical units feared to tread. In addition to nursing, caring and cooking for soldiers, one of her most significant contributions came towards the end of the war when families sought information about missing loved ones. Then President Lincoln wrote: “To the Friends of Missing Persons: Miss Clara Barton has kindly offered to search for the missing prisoners of war. Please address her . . . giving her the name, regiment, and company of any missing prisoner.” Over four years she and her team responded to over 63,000 letters and identified over 22,000 missing men. Today the Red Cross still provide this searching service and describe it as one of their most valued activities.

Image: Nobel

Irene Joliot-Curie had rather big scientific shoes to fill, with her parents Marie and Pierre Curie having both earned Nobel Prizes. Yet fill them she did - sharing the 1935 Nobel Prize for Chemistry with her husband Frederic Joliot. Irene worked with her mum to provide mobile X-ray units during World War I, returning to her studies in Paris before going on to work at the Institut de Radium which had been founded by her parents. It was here that she and her husband bombarded a piece of aluminium with alpha particles, artificially creating a radioactive substance for the very first time and earning them a Nobel Prize.

Rebecca Lee Crumpler made history in 1864 when she became the first African American woman to be awarded a medical degree. Little is known about her life, and despite her massive achievement no images of her exist today. What we do know of her comes from her 'Book of Medical Discourses', whose existence is further testimony to her intelligence and fortitude as it was one of the first medical publications by an African American. Reflecting on why she had entered into medicine she said: "It may be well to state here that, having been reared by a kind aunt in Pennsylvania, whose usefulness with the sick was continually sought, I early conceived a liking for, and sought every opportunity to relieve the sufferings of others.” Her desire to alleviate suffering was such that she treated children without concern for their parents ability to pay her.

If you’re interested in more impressive women, there’s a helpful (though woefully short) list of female Nobel Laureates available here. The NIH also has an interesting project called Changing the Face of Medicine which celebrates female physicians.

In the week of Galentine’s Day, I’d like to say a big thank you to these women and to all the strong women I’m lucky to have in my life. I look forward to raising my little feminist with my staunchly feminist hubbie, and maybe toots will follow in the footsteps of these illustrious women. Or maybe she’ll carve her own unique path. Whatever road she chooses I hope she’ll know that well-behaved women rarely make history.

Tuesday, 22 July 2014

Every writer needs a muse. Today, mine is diarrhoea.
Inspired by the recent norovirus outbreak at the Glasgow Commonwealth Games I
thought I’d write a few words on this intestinal disruptor. There will be
images, and they will be beautiful. I promise.

Norovirus is a social butterfly. It spreads readily from
person to person, casually disregarding social etiquette and even Michelin
stars. In the spring of 2009 it descended upon Heston Blumenthal’s £200 a head
restaurant The Fat Duck. It was the largest ever norovirus outbreak at a UK restaurant,
with at least
240 people gushing out their haute cuisine. In the aftermath it became
apparent that the most likely source was a batch of contaminated oysters.

A fact not to be shared over a romantic dinner is that this
alleged aphrodisiac often harbours norovirus. A 2011 study by the Food
Standards Agency found that 76% of
British oysters tested were contaminated. Like us, oysters unwittingly
consume the virus from human sewage. As filter feeders they churn huge volumes
of water through their bodies to extract food and during this process they can
accumulate any viruses and bacteria contaminating the water. There are industrial
techniques that aim to purge these contaminants from oysters by leaving them in
clean, UV irradiated water for a few days before harvesting. However it’s
unclear how effective this approach is for norovirus. On the plus side, even eating
norovirus contaminated oysters won’t necessarily result in harm- that depends
on the health of the person eating them and the concentration of viral
particles. Nevertheless, you’d be forgiven if this undermines your faith in Cosmopolitan’s
assertion that swallowing this raw grey bivalve mollusc “really
can spark randiness”.

The conduit for the recent Glasgow Commonwealth
Games norovirus outbreak was less glamorous: a temporary toilet. So far
there have been 53 suspected cases amongst the staff, who are a bathroom-hovering
microcosm of a global problem- every year norovirus causes 267
million infections worldwide. Inside the guts of the Glasgow staff norovirus
will have set to work with its toolkit, entering cells and hijacking their
machinery to make new norovirus particles. What makes this heist particularly
impressive is that the virus has just nine
protein-coding genes in its repertoire. For contrast fruit
flies have 13,000. By leveraging the cells’ own resources the norovirus is
able to set up an epic production line that creates billions of new viral particles.
Then with an efficiency that would make even Amazon envious, norovirus sets
about dispatching from its human factory to the outside world. Which is where
things get unpleasant. We don’t know how, but the virus hijacks the nervous
system and sends signals to the stomach to make it contract violently and vomit.
This generates tiny droplets, which float through the air, dispersing the virus
onto surrounding surfaces. The next unsuspecting host has to transfer just 18 viral
particles to their mouth to become ill.

Not content with one exit strategy, norovirus also causes
diarrhoea. It achieves this by increasing the amount of fluid escaping through
the lining of the intestine. In a healthy gut, the cells that line the
intestine are held together by protein linking-structures called tight junctions.
These are demonstrated as continuous blue lines in the left-hand image below. Norovirus
disrupts these tight junctions, which makes the gut leaky and causes watery
poo. E. coli takes a similar
approach, and in the right-hand image we can see how the red dots (E. coli) have proliferated and the tight
junctions have been broken-down. The remnants of the tight junctions exists as
discontinuous blue dots, which are no longer capable of stopping water leaking
between the cells and out into the intestine.

In its quest for a steady stream of diarrhoea, norovirus
also increases
the number of chloride ions pumped by cells into the intestine. Water
follows the lead of the ions in a process called osmosis. This potent
combination of leaky tight junctions and increased osmosis enables norovirus to
generate diarrhoea.

It’s been estimated that a single gram of poo from an
infected person
contains 100 billion viral particles. That means there are ten times more norovirus
particles in a gram of infected poo, than there are people on the planet. Which
perhaps allows Glasgow and Heston to take comfort from the fact that they were
beaten by a virus that’s disgustingly good at spreading itself.

Monday, 5 August 2013

Have you ever watched
someone die? Almost everybody has. Ok, so not in real life but on TV or in a
film? Deaths are used by writers to make us laugh or cry, but
I've watched two this week which, well, irritated me. Instead of being sucked
into the emotional tragedy unfolding before me, I sat muttering ”well that
wasn't very realistic”. Now, I am the queen of suspending disbelief- I've
watched Neighbours for over 25 years, my Freeview recorder has 169 episodes of
Murder, She Wrote on it (Angela Lansbury makes me want to be old) and I believe
that Jack Bauer really could do all that AND MORE in 24hrs. But even my
imagination couldn’t keep me in TV land when faced with Queen Eva's death in Once Upon a Time this week. I
was sucked out of the story and spat out onto the sofa by the absurdity of it.
An immaculately beautiful woman imparted an eloquent, heartfelt message before
dying in a neat, quick and quiet way. You could almost feel her holding her
breath. No death rattle for Queen Eva.

But that was a fairy-tale,
she was poisoned, maybe magically cursed people do die just like that. (The
Oxford Handbook of Clinical Medicine was no help in this matter). But Queen Eva
wasn't the only irksome death of the week- I felt just as bothered by the
departure of Raj from 90210.
Yes, my name is Catherine and I watch 90210…it’s like the crack of TV,
so bad, yet you just can’t stop it, and your husband doesn't understand why you
keep going back to it. Anyways, there I was, enjoying my fix of emotional highs
and lows delivered by the beautiful people. Raj was in hospital looking a little
hungover. We know he’s close to death, purely because we've been told so, but
he's chatting away, being witty, romantic and thoughtful. Then his girl pops
out for a second and returns to find him dead. We know he's dead because his eyes are shut and she drops a glass of water. Again it’s neat, quick and
quiet. Bothersomely so.

You
see people in TV land, like Raj and Eva, die without dying. In the real world,
death is an event, but dying is a process. Noisy, irregular breathing, semi-consciousness,
confusion, a dry mouth, restlessness- these are often very normal parts of dying.

Yet we
don’t often see this on TV, despite the fact that a LOT of people die in soaps.
A study of soap characters in the BMJfound
that “standardised mortality ratios for characters were among the highest for
any occupation yet described”. The authors noted that “Their lives are more
dangerous even than those of Formula One racing drivers or bomb disposal
experts”. But despite this obsession with death, TV hates people dying. Perhaps
because it’s too upsetting? Yet, think of a soap wedding- we expect it to be
upsetting, we KNOW there are very few happily ever afters in soap land. TV
expends a huge amount of effort in creating drama and wringing every ounce of emotion
from an audience. So it seems strange that dying a soap death is as simple and
sanitized as you could hope for. Does this suggest dying, more than death, is a
taboo too shocking for TV?

I know that reality isn't
what these programmes are made for, but they are based firmly in our world.
Music we know plays in the pub, there are frequent references to Facebook and everyone in Ramsay Street has an ill-disguised mac book. These shows tell stories about people
and they're watched by millions. That means they have incredible potential to
influence our expectations of what normal is. Is TV making us think it’s normal
to die without dying? If so, a lot of us are ill prepared for when death forces
its way from our screens and into our lives.

Think back to the last time
you watched someone die in TV or film land. Did you really watch them die, or
just see a death?

C.diff
typically arises due to imbalances in your normal gut bacteria. You
see your gut is like a city, a city with about 100 trillion bacterial
residents happily munching away on a banquet of bowel contents. The
average person has about 1000 different types of bacteria in their
gut, and about 3% of healthy adults have C.diffin that
mix. The
C.diff doesn't cause them any problems because its numbers are kept
in check by the other gut bacteria. However treatment with broad
spectrum antibiotics can disrupt this happy community, killing off
vast swathes of bacteria but crucially not the C.diff which is
particularly hardy. Given free rein the C.diff multiplies rapidly and
produce toxins which damage the gut. In some people this causes mild
diarrhoea and abdominal pain, in others it can lead to torrential
diarrhoea, perforation of the colon and death.

Traditional treatment involves stopping the broad spectrum antibiotics and
prescribing antibiotics which specifically target the
C.diff.
However C. diff is becoming resistant to these antibiotics and about 22% of patients who are treated then relapse.
This can result in a cycle of illness and hospital admission which is
costly to the patient and the hospital.

So
it's time to start thinking outside of the box. Cue the poo
transplant. The thinking goes like this- if the cause of the problem
is disruption to the normal community of gut bacteria, why not just
pop those bacteria back in to crowd out the C.diff? Simples.
Practically, the first step is to identify a donor, usually a close
relative of the patient, and screen them for a range of infectious
diseases and parasites. You should also make sure they haven't
recently consumed anything the intended recipient is allergic to,
before asking them to make their "donation". You then pop it in a
household blender, adding salt water or milk to achieve a slurry
consistency and blitz it down. Next you need to strain your
concoction to remove large materials- one medic in the UK uses coffee filters. Top tip. Then you're ready to administer it- about 25ml from above (via a tube
into the stomach), or 250ml from
below.

Now,
its important to note that poo transplants are experimental. To date
only small case studies have been carried out, but with 200 total
reported cases, an average cure rate of
96%and no serious adverse events reported to date, it's worth carrying
out a large trial to assess it thoroughly.

So,
poo transplants-the ideal treatment for a cash strapped NHS. Its
cheap, plentiful and it seems to
work.
We just have to convince people to consume someone else's poo....or,
let us pop it in their bums. Bottoms up!

Sunday, 3 March 2013

I'd
like to tell you a curious story. Jane was a 52 year old woman in
need of a kidney transplant. Thankfully she had 3 loving sons who
were all very happy to give her one of theirs. So Jane's doctors
performed tests to find out which of the three boys would be the best
match, but the results were surprising. In the words of Jeremy
Kyle, the DNA test showed that Jane was notthe mother of two
of the boys... Hang on, said Jane, childbirth is not something you
easily forget. They're definitely mine. And she was right. It turns out Jane was a chimera.

Chimerism
is the existence of two genetically different cell lines in one
organism. This can arise for a number of reasons- it can be
caused by medics, like when someone has an organ transplant, or be naturally
occurring. In Jane's case, it began in her mum's womb, with two eggs
that had been fertilised by different sperm creating two embryos. Ordinarily, they would develop into two non-identical twins. However in Jane's case the two
balls of cells fused early in development creating one person with both cell lines.

Thus
when doctors did the first tissue typing tests on Jane, just by
chance they had only sampled the 'yellow' cell line which was
responsible for one of her sons. When they went back again they found
the 'pink' cell line which had given rise to the other two boys.

This
particular type of human chimerism is thought to be pretty rare-
there are only 30 case reports in the literature. (Though remarkably
both House and CSI's Gil Grissom have encountered cases.) What happens
far more frequently is fetal microchimerism- which occurs in pregnant
women when cells cross the placenta from baby to mum. This is awesome
because we used to think the placenta was this barrier which
prevented any cells crossing over. Now we've found both cells and
free floating DNA cross the placenta, and that the cells can hang
around for decades after the baby was born. Why? As is often the case
in medicine we're not sure but one theory is that the fetal cells
might have healing properties for mum. In pregnant mice who've had a
heart attack, fetal cells can travel to the mum's heart where they develop into new heart muscle to repair the damage.Whilst
we're still in the early stages of understanding why this happens, we
already have a practical application. In the United States today, a
pregnant woman can have a blood test which isn't looking for
abnormalities in her DNA, but in that of her fetus. The DNA test isn't
conclusive enough to be used to diagnose genetic conditions in
isolation, but it is a good screening test for certain conditions including
Down's syndrome.Now,
we started with a curious tale, so let's close with a curious fact and one that's appropriate for Mother's Day:
This exchange of cells across the placenta is a two way process. So
you may well have some of your mum's cells rushing through your veins
right now. In my case they're probably the ones that tell me to put
on sensible shoes and put that boy down...This post is based on a presentation I gave at the 2013 FameLab regional finals.

Then
two events shifted my perspective: the death of a loved one and a
political triumph.

Coffins
are small. They house a body, but they can never hold a person. My
cousin baked the most amazing biscuits I'll ever eat, she loved music
and had unending patience for jigsaws. She was kind and generous and
irreplaceable. These things, the things that made her who she was,
live in my heart and in every person who was lucky enough to know
her. She died in her forties from lung cancer.

This
year, my optimist was brought back fighting by the Australian
government. 2012 was the year that Australia passed a plain packaging
law to standardise cigarette packets (6). Goodbye camels and cowboys,
hello disease addled eyes and cancer ridden lungs on a murky green
background. Lest we forget who is responsible for selling these
deadly wares, companies can put their name on the packet in a dull,
diminutive font. It has been said this will have no impact on
smoking, but the tobacco companies' reactions tell a different story.
British American Tobacco, Imperial Tobacco, Philip Morris and Japan
Tobacco all took legal action against the Australian government,
claiming the law violated the companies' intellectual property
rights. Philip Morris also asserted the law would contravene a
bilateral trade agreement with Hong Kong that would leave the
government liable to pay Philip Morris huge amounts in compensation
(7). Thankfully the Australian High Court ruled that the laws were
sound and they will come into force in December 2012. The perfect
Christmas present for Australian hearts and lungs.

We
can even make our own relatable statistics. Philip Morris' Richmond
plant in Virginia, USA made 146 billion cigarettes in 2010. That's
146,000 deaths. The Kunming Cigarette Factory in China made just 71
billion that year, a paltry 71,000 deaths (10). Between these two
factories, in a single year's production they will kill the
equivalent of every man woman and child in the town I was born in. 54
times over. Don't feel left out, its a game we can all play.

Alloftheseideasarebigandbraveandmassivelyproblematic,muchliketakingonthetobaccoindustry.Together,thebiggesttobaccofirmsmakemorethan$1,100ofprofitasecond(14),sotheyhavemuchtoloseifsmokingdeclines.ThisfactwasfeltbytheAustralianhealthdepartmentwhentheywerepassingtheplainpackagingbillthroughparliament.Theteamwere
“swamped”
by63freedomofinformationrequests,52ofwhichwerecourtesyoftobaccocompaniesinwhathasbeendescribedbycommentatorsas
“aspecificanddeliberateattempttodivertresources”
(15).Disappointingly,
tobacco companiesarebeingaided
in their efforts to maintain power and profitbythepoliciesofsomecountries.TheWHOFrameworkConventiononTobaccoControlcameintoforcein2005andwasalandmarkachievementininternationalpublichealth.Itsetsminimumstandardsfortobaccocontrolwhicharelegallybindingin176countries,coveringeveryaspectoftheindustryfromproductiontomarketingandtaxation.Yet,evenunderaDemocraticPresidentwithavocalcommitmenttohealthcaretheUnitedStateshasnotratifiedtheconvention(16).Clearlythereisalongwaytogobeforemyhopesarerealised.

The
tobacco industry has the audacity to make millions of dollars selling
an addictive product which causes millions of deaths. We must be as
smart, as ambitious, as bold as they are. If ever there was a man who
captured all of these qualities it was Apple's visionary leader Steve
Jobs. In 2005 at Stanford University he delivered the most moving and
inspiring piece of public speaking I've ever heard. His advice was to
“Stay hungry. Stay foolish.” This is the mantra public health
needs- from smoking to obesity, from malaria to HIV, it is imperative
we think big. When devising solutions we shouldn't just accept our
limitations, instead we must push them, shove them, shatter them.
Stay hungry. Stay foolish. That's my truth, now tell me yours.

About Me

A little grey cell is a collection of stories from the worlds of science and medicine.
My first book 'Immune' holds a treasure trove of stories about how the body defends and protects us from the millions of microbes out there. It also highlights how the immune system is intertwined with our daily lives, from cursing us with allergies to perhaps influencing who we fall in love with! It's available to pre-order on Amazon here: https://www.amazon.co.uk/Immune-Your-Body-Defends-Protects/dp/1472915119/ref=tmm_hrd_swatch_0?_encoding=UTF8&qid=1488302845&sr=8-1